Lexéma

Lexéma, also known as lexeme in many linguistic traditions, is the fundamental unit of lexical meaning that underlies a family of related word forms. It represents an abstract mental unit, distinct from the particular surface form that is realized in speech or writing. A single lexéma can generate a range of inflected or derived forms that share the same core meaning.

In practice, a lexéma encompasses all the morphologically related forms that express the same lexical content. For example, the English verb go has the forms go, goes, going, went, and gone, all of which belong to the same lexéma. The different spellings and pronunciations are surface realizations of the same underlying unit.

A related concept is the lemma, the canonical or dictionary form used to represent a lexéma. The lemma is often the base form of a word (such as go for the verb) and serves as the entry point in dictionaries and many linguistic analyses. While the lemma often coincides with the most common surface form, the relationship between lemma and lexéma can vary between theories.

Lexèmes are distinguished from morphemes, the smallest units of meaning. Morphemes compose word forms; a lexéma, by contrast, is a higher-level abstraction that groups all forms sharing the same semantic content. In fields such as lexicography and natural language processing, lemmatization and morphological analysis map inflected forms to their corresponding lexèmes.

The term is used across languages, with slight variations in spelling (for example, lexème in French, lexéma in some languages), but the underlying idea remains the same: a lexéma is the abstract unit of meaning behind a set of related word forms.